2. The inset image is of a 0.5mm wide pencil lead;
it is equivalent to one Upper Medium grain or
eight Lower Very Fine sand grains (coarsest Silt).
3.
4. Lower Very Fine
Upper Very Fine Upper Coarse Silt 0.5mm wide
The pencil lead is for scale and is 0.5mm wide; the inset image on the pencil lead indicates the grain size
measurements. The width of the pencil lead is equivalent to the width of 1 Medium sand grain, 2 Upper
Fine sand grains, 4 Upper Very Fine sand grains, 8 Lower Very Fine sand grains. The Lower Very Fine grain
size is equivalent to the Upper Coarse Silt grain size; silt grains are even smaller than the yellow circle shown
here in the inset image.
UVF
5. The pencil lead is 0.5mm wide. Equivalent to one Upper
Medium sand grain, two Upper Fine, four Upper Very Fine or
eight Lower Very Fine sand grains. The Lower Very Fine grain
size is equivalent to the coarsest Silt size grains.
6. The pencil lead is 0.5mm wide. Equivalent to one Upper
Medium sand grain, two Upper Fine, four Upper Very Fine or
eight Lower Very Fine sand grains. The Lower Very Fine grain
size is equivalent to the coarsest Silt size grains.
7. The pencil lead is for scale (0.5mm wide) the inset image on the pencil lead indicates the grain size measurements. The
width of the pencil lead is equivalent to the width of 1 Medium sand grain, 2 Upper Fine sand grains, 4 Upper Very Fine
sand grains, 8 Lower Very Fine sand grains. The Lower Very Fine grain size is equivalent to the Upper Coarse Silt grain size;
silt grains are even smaller than the yellow circle shown here in the inset image.
8. These images are cuttings samples from an oil bearing sandstone reservoir. The cuttings
samples on top are oil stained (very light tan) while the cuttings samples on the bottom are
heavily cemented with calcite cement and are not oil stained (dirty white to cream). The pencil
lead is for scale (0.5mm wide).
9. These images are cuttings samples from an oil bearing sandstone reservoir. The cuttings
samples on top are oil stained (very light tan) while the cuttings samples on the bottom are
heavily cemented with calcite cement and are not oil stained (dirty white to cream). The pencil
lead is for scale (0.5mm wide).
10. Sandstone: Medium gray to grayish brown and occasionally tan, coarse silt to upper very
fine grained, trace lower fine grained, locally grading to sandy siltstone, rounded to sub
angular, well sorted, fair to moderate calcareous cement, good, grading to very good
intergranular porosity, estimated 15-20%, trace black carbonaceous material.
Note: what may appear to be a single grain (below the inset UF) is a cluster of grains.
Upper Very Fine
11. This is an image of cuttings samples for an oil bearing sandstone reservoir (interval: 4150-4190mMD) taken with both Ultraviolet light (UV)
and White Light (WL). The inset image is of a single cutting chip photographed using a microscope (10X magnification); the pencil lead is for
scale (0.5mm wide). This cutting is representative of the best oil staining in this sample interval which also has the brightest fluorescence
under UV light. The sample was then tested for cut by the application of a solvent.
12. Sandstone: Very light tan, uniform oil stain, the inset image is calibrated to the pencil lead which is for scale (0.5mm wide). One sand grain is
highlighted (red arrow) indicating that it is Upper Very Fine grain size. The circle highlighted with yellow colored fill is a Lower Very Fine grain
size which is equivalent to the coarsest Silt; silt grains are even smaller. This sandstone cutting is upper very fine to upper coarse silt grain
size.
UVF
Upper Very Fine
13. Lower Very Fine
Upper Very Fine Upper Coarse Silt 0.5mm wide
The pencil lead is for scale and is 0.5mm wide; the inset image on the pencil lead indicates the grain size
measurements. The width of the pencil lead is equivalent to the width of 1 Medium sand grain, 2 Upper
Fine sand grains, 4 Upper Very Fine sand grains, 8 Lower Very Fine sand grains. The Lower Very Fine grain
size is equivalent to the Upper Coarse Silt grain size; silt grains are even smaller than the yellow circle shown
here in the inset image.
14. Lower Very Fine
Upper Very Fine Upper Coarse Silt 0.5mm wide
UVF
The pencil lead is for scale and is 0.5mm wide; the inset image on the pencil lead indicates the grain size
measurements. The width of the pencil lead is equivalent to the width of 1 Medium sand grain, 2 Upper
Fine sand grains, 4 Upper Very Fine sand grains, 8 Lower Very Fine sand grains. The Lower Very Fine grain
size is equivalent to the Upper Coarse Silt grain size; silt grains are even smaller than the yellow circle shown
here in the inset image.
15.
16.
17.
18.
19. Spot sample taken 3840m MD (this is good reservoir). Pencil lead is 0.5mm wide (the width of
one medium sized sand grain; two Upper Fine; four Lower Fine or eight Lower Very Fine grains).
This sandstone cutting is upper very fine to upper coarse silt grain size. Lower Very Fine is
equivalent to Coarse Silt. Silt is even smaller than the circles shown here.
UVF = LF
LVF
20. Spot sample taken 3840m MD. The two samples (good/poor) reservoir sandstone have
been separated. The color is better in this photo than the previous slide.
21. Spot sample taken 3840m MD. With higher magnification the color of the stain looks lighter
than on the previous slide.
22. Spot sample taken 3840m MD. With higher magnification the color of the stain looks lighter
than on the previous slide.
23. Spot sample taken 3840m MD. With higher magnification the color of the stain looks lighter
than on the previous slide.
